1. Field of the Invention
The present invention relates to a lighting fixture for a vehicle, and more particularly, to a lighting fixture for a vehicle that has an improved waterproof cover in the inner aiming type headlight.
2. Background Art
In a conventional headlight for a vehicle in which a lamp-holding reflector is so fixed as to tilt freely in a headlight housing fixed to a car body, the housing has an opening for lamp replacement in the rear thereof. Such an opening needs waterproof means to keep rainwater, dust, and grit out of the opening. FIGS. 3 and 4 show conventional examples of a lighting fixture for a vehicle having such a waterproof construction.
FIG. 3 will be first described hereinafter. A lamp housing 30 is fixed to a car body (not shown). Opening 31 is formed in the center of the rear of the housing 30. Annular mounting part 32 protruding rearward is formed around the edge of the opening 31. Mating edge 33 protruding in the radial direction is formed around the rear-end edge of the said annular mounting part 32.
A reflector 34 is supported in the lamp housing 30 so that it can tilt freely. A lamp 35 is supported in the center of the rear of the reflector 34 so that the lamp can be inserted into or removed from the reflector.
A waterproof cover 36 comprises a cylindrical fit part 37 to be fit on the outer diameter part of the lamp 35 and a cylindrical part 38 to have the lamp housing 30 fitted into it. The cylindrical fit part 37 is connected to the cylindrical part 38 through bellows-like intermediate part 39. The inside circumferential surface of the cylindrical part 38 has mating groove 40 which mates with the mating edge 33 of the lamp housing 30.
According to the above configuration of a conventional lighting fixture for a vehicle, the space between the lamp 35 moving with a tilting reflector 34 and the opening 31 in the lamp housing 30 is waterproofed by the waterproof cover 36.
However, the waterproof cover 36 is fit directly into the lamp 35 and the waterproof cover 36 must be removed from the lamp housing 30 when the lamp 35 is replaced. For this reason, the above-mentioned lighting fixture for a vehicle has problems such as possibly the waterproof cover is reattached incompletely to the lamp or the waterproof cover is damaged, thus resulting in a drop in its waterproof performance.
FIG. 4 shows another conventional example of a headlight for a vehicle so constructed as to use a waterproof cover not fit directly into a lamp to solve the above problems and make it possible to replace the lamp without removing the waterproof cover from the lamp housing.
A lamp housing 43 is mounted and fixed to a car body (not shown). The lamp housing 43 has an opening 44 in the center of the rear thereof.
A cylindrical mounting part 45 of the said opening 44 protrudes rearward. The said mounting part 45 comprises a smaller-diameter cylindrical front-half part 45b and a larger-diameter cylindrical rear-half part 45a. A mating piece 47 protrudes like a flange between these cylindrical parts in the radial direction. A bumping edge 46 which protrudes toward the center of the housing in a radial direction is formed at the end edge of the mounting part 45.
A reflector 42 has an opening 48 in the center of the rear thereof. A cylindrical mounting part 49 is formed rearward around the edge of the opening 48. A lamp is inserted into the mounting part 49 such that a lamp socket is in close contact with an inside circumferential surface 49a the mounting part.
A cylindrical wall part 50 is formed around the mounting part 49 and the cylindrical wall part 50 has a larger diameter than that of the mounting part 49 and surrounds the mounting part 49. An external cylindrical wall part 51 is formed around the cylindrical wall part 50 and the external wall part 51 has a larger diameter than that of the cylindrical wall part 50 and surrounds the said cylindrical wall part 50.
A block-like connecting part 63 connects the cylindrical wall part 50 to the external cylindrical wall part 51. The rear end of the connecting part 63 is provided with a screw hole 64.
A retainer ring 52 is provided to fix the lamp 41. The retainer ring 52 is fixed to the block-like connecting part 63 with a screw 65 to fix the lamp firmly.
A waterproof cover 53 has a cylindrical fit part 54 in a central portion of the cover, a cylindrical mounting part 56 located on the peripheral portion thereof, and a thin intermediate part 55 connecting the cylindrical fit part 54 to the cylindrical mounting part 56.
The said fit part 54 is pressure-fit into close contact with the external cylindrical wall part 51 of the reflector 42. A retainer ring 57 comprises an annular retaining part 58, a side wall part 59, and a mating part 60. The said mating part 60 has a mating piece 61.
The mating part 60 mates with the mating piece 47 of the lamp housing 43 when the waterproof cover 53 is turned while pushed. At the same time, the mounting part 56 of the waterproof cover 53 then comes into contact with the rear-half part 45b of the lamp housing 43 and is pushed by the retainer ring 57 to seal the space between the mounting part 56 and the rear-half part 45b.
As described above, the above-mentioned waterproof cover is not fit directly into the lamp. That makes it unnecessary to remove the waterproof cover from the lamp housing every time the lamp is replaced, thus reducing the possibility of damage to the waterproof cover once it is attached to the lamp housing completely. In addition, the waterproof cover will never be reattached to the lamp housing incompletely once it is attached completely, resulting in no possibility of a drop in the waterproof performance of the cover.
However, in the headlight for a vehicle shown in FIG. 3 and the improved headlight for a vehicle shown in FIG. 4, the central cylindrical fit part of the waterproof cover is pressure-fit into close contact with the external cylindrical wall part provided for the lamp or reflector and the fit part is exposed. Consequently it has been thought that an unexpected touch with or push on the exposed fit part by a user would lead to a drop in the waterproof performance of the cover. In addition, the waterproof cover in the conventional example shown in FIG. 4 requires a retainer ring. The resulting larger number of parts has made the construction of the waterproof cover complicated and the waterproof cover troublesome to build.